Used to Know
by ImagineAsian101
Summary: Clary meets Tessa at one of Magnus's parties. Jace and Simon remind Tessa of some people that she used to know... -ONESHOT- :D


**A/N: Finished Clockwork Angel. Loooved it. Awaiting Clockwork Prince and Princess! :D **

**Therefore, I bring you my first crossover, ever, that happens to be Mortal Instruments and Infernal Devices. Let's assume Tessa is truly a warlock, too. This is what would happen, in my opinion, if they met. :)  
**

**Disclaimer: Characters belong to miss Cassandra Clare!**

* * *

"So, these Downworlders are all warlocks?" asked Alec as he weaved through the crowd, holding Magnus's hand.

"Yep. I've been selected to hold Lilith's Ball, a Warlocks Only party," Magnus replied, dabbing at his golden eyeliner.

"Then how are we here? We're shadow hunters! Plus a vampire," his boyfriend gestured at Izzy, Simon, Clary, and Jace.

"As host, I get a few exceptions," winked the midnight black-haired warlock, gripping Alec's hand and tugging him to the dance floor.

* * *

Meanwhile, Clary pressed against Jace, somewhat frightened by the medley of spell casting, strobe lights, and glitter.

"You alright?" Jace yelled over the music, even though she was right beside him.

"Uh, yeah!" Clary hollered back. "Bathroom," she mouthed. Jace kissed her forehead and untangled his arm from her waist.

Her strawberry locks, once straightened by Isabelle, were beginning to frizz up again as she wiggled and squirmed through the dancing group of Lilith's children. Finally, she saw the light at the end of a less-crowded hallway and made a b-line for it.

Clary gulped some fresh, non-alcoholic smelling air and leaned against the stone walls... that felt strangely like a shoulder. Clary turned around and realized she'd bumped into a warlock. "Oh, sorry!"

"It's alright," the Downworlder replied, tucking a brunette strand of hair behind her ear. Something about her seemed Victorian-esque and colonial.

"I'm Clary."

"Tessa," she replied with a smile.

"I love your accent," Clary blabbed before realizing how stupid she sounded.

"Why, thank you. It's British. Likewise, I enjoy the Brooklyn style of speaking," Tessa grinned. Suddenly, her smile faded as she saw Magnus approaching. "Shit, he's probably mad at me for beating him at a game of cards yesterday. He's way too competitive!"

In a blink of an eye, Tessa plucked a strand of Clary's red hair and began to glow. Her features, such as the dainty nose, morphed into Clary's bunny sloped one, followed by a sprinkle of freckles. Red slowly crept up the dark brown locks of Tessa's hair and emerald green irises replaced her steady gray.

Clary drew in a breath as she stared at... herself, only to be pushed into a corridor as Tessa took her place.

"Clary, are you having fun?" she heard Magnus ask.

"Yeah, just breathing in some fresh air," Tessa, as Clary, perfectly chimed in. That was exactly what the real Clary was thinking.

"You better go back to Jace. Some of the more rowdy female warlocks are beginning to gang up on him," smirked Magnus. Clary listened as his footsteps faded away before stepping back out.

"Sorry about that," Tessa laughed, changing back to herself mid-sentence.

"Whoa... How did you do that?" asked the Shadowhunter.

"I'm an Eidolon; shape shifter," Tessa shrugged.

Just then, Jace came in as he swatted away at a bunch of warlocks. "Downworlders, downworlders, keep your spells and potions to yourself! This is my beloved Clary, the one who owns my heart and has the right to fawn over my good looks," he dramatically sighed. The women scoffed and walked away.

"There you are. And you've made a friend!" Jace laughed, hugging Clary to him. Tessa looked at him skeptically and nodded.

At the same time, Simon waltzed in.

"Hey, Clary! There you are. I got you a drink," the Daylighter said, Isabelle trailing behind him. Tessa said nothing, once again.

"This is Tessa," Clary introduced her to everyone.

Jace held out a hand, only to be interrupted by some random Downworlder. "Jace Herondale! I've always wanted to meet you!"

"It's Jace Lightwood, but, nice meeting you, too." Jace turned away. Simon and Izzy walked off.

Tessa was rigid. "Herondale?"

"Yeah, he's Stephen Herondale's son, but they never really knew each other, if that makes sense," Clary gave the simplified version. She noticed Tessa's pale complexion. "Are you okay?"

"Yes... It's just that your two friends remind me greatly of two boys," the warlock murmured.

"Really? What were they like?"

"One was a plain old mystery. He might've seemed sarcastic, arrogant, and somewhat tortured, but he was willing to risk his life for others. Selfless. Afraid to love, but willing to try. And the other one was kind and lighthearted. Strong. Lived with health problems, but still pressed on," Tessa reminisced.

"I guess that does sound like Jace and Simon. Do you ever see these people around?"

"No... They're just some people that I used to know."


End file.
